Title :
Highly Sensitive Optical Multilevel Transmission of Arbitrary Quadrature-Amplitude Modulation (QAM) Signals With Direct Detection
Author :
Kikuchi, Nobuhiko ; Sasaki, Shinya
Author_Institution :
Central Res. Lab., Hitachi Ltd., Kokubunji, Japan
Abstract :
A proposal for the realization of highly sensitive optical direct-detection (incoherent) multilevel transmission with arbitrary signal constellation without optical chromatic dispersion (CD) compensation is reviewed in this paper. We introduce transmitter-side signal processing, ??CD pre-equalization,?? and ??phase preintegration?? techniques to realize direct-detection CD-compensation free transmission of arbitrary optical quadrature-amplitude modulation (QAM) signals. We also adopt receiver-side signal processing, ??multi-symbol phase estimation (MSPE),?? and ??non-Euclidean metric-based symbol detection?? to improve the optical SNR (OSNR) sensitivity. We have performed up to 160-km standard single-mode fiber transmission of a 40-Gbit/s 16QAM signal and achieved the OSNR sensitivities only 0.5-2.4 dB away from those of coherent detection.
Keywords :
optical fibre dispersion; optical fibre networks; optical modulation; optical receivers; phase estimation; quadrature amplitude modulation; CD pre-equalization; arbitrary optical quadrature amplitude modulation; arbitrary signal constellation; bit rate 40 Gbit/s; direct-detection CD-compensation free transmission; highly sensitive optical direct-detection multilevel transmission; multi-symbol phase estimation; nonEuclidean metric-based symbol detection; optical SNR sensitivity; optical chromatic dispersion compensation; phase preintegration; receiver-side signal processing; single-mode fiber transmission; transmitter-side signal processing; Adaptive equalizers; amplitude shift keying; differential phase-shift keying; multilevel systems; optical fiber communication; optical modulation; quadrature-amplitude modulation (QAM);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2009.2035827
